fix: json.loads JSONB overrides on GET — asyncpg has no codec registered

asyncpg returns JSONB columns as raw JSON strings when no type codec is
configured (only pgvector is registered in _init_connection). The stored
value is a correct JSONB array (jsonb_typeof=array confirmed), but
asyncpg decodes it as str. Parse it explicitly in the GET handler so
the frontend receives the correct Python list/dict.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/app.py

@@ -3057,8 +3057,16 @@ async def api_get_methodology(category: str):
     items = {}
     for key, default_val in defaults.items():
         if key in overrides:
+            raw = overrides[key]["rule_value"]
+            # asyncpg returns JSONB as a raw JSON string when no codec is registered.
+            # Parse it back to a Python object so the frontend receives the correct type.
+            if isinstance(raw, str):
+                try:
+                    raw = json.loads(raw)
+                except (json.JSONDecodeError, TypeError):
+                    pass
             items[key] = {
-                "value": overrides[key]["rule_value"],
+                "value": raw,
                 "is_override": True,
                 "updated_at": overrides[key]["created_at"].isoformat() if overrides[key]["created_at"] else None,
             }